Heater for wash tanks



Sept. 16, 1958 c. L wER 2,852,139 v HEATER FOR WASH TANKS Filed May 5, 1956 v INVENTOR, CHARLEY LOWERY ayw/ p A'rmmygr United States" Patent 9 HEATER FOR WASH TANKS (Iharley Lowery, Oklahoma City, ()kla.

Application May 3, 1956, Serial No. 582,560

7 Claims. (Cl. 210-187) This invention relates generallyto improvements in the art of processing crude oil, and more particularly to a novel heater construction for crude oil wash tanks.

As it is well known in the art, crude oil and water produced from oil wells is usually circulated through a wash tank containing a substantial amount of brine water to remove the water from the crude oil, and to at least partially remove other foreign matter from the crude prior to storage of the crude oil in stock tanks in the vicinity of the well site. Also, a heater is usually disposed in the wash tank to heat the crude oil and facilitate removal of water therefrom. These present day heaters are rigidly secured in the wash tanks, whereby the heaters are not free to expand and contract with changing temperature conditions. In addition, the present heaters and the fluid inlets to the wash tanks are arranged in such relative positions that a large portion of the water contained in the tanks is unnecessarily heated, thereby absorbing and wasting a large portion of the heat generated by the heater. Furthermore, salt from the wash tank brine water deposits on the heaters to decrease the efliciency of heat transfer and require frequent shut-down of the tank for cleaning the heater.

The present invention contemplates a novel wash tank heater which may be arranged in the wash tank in such a manner with respect to the wash tank inlet as to provide a fall-out or knock-out of the free water from the incoming crude below the heater proper. Therefore, the majority of the water introduced into the wash tank will be removed below the heater and will not be appreciably heated during its movement through the tank. I also contemplate securing the heater in a cantilevered manner in one wall of the wash tank, and the elements of the heater are telescoped, whereby the heater may freely expand and contract during changing temperature conditions. A fresh water spray device is arranged'in the upper portion of the heater to periodically spray fresh water on the top of the fire box of the heater, whereby salt depositing on the heater and interferring with transfer of heat into the wash tank may be periodically washed off or removed without the necessity of removing the heater from the wash tank.

An important object of this invention is to efliciently utilize the heat generated in crude oil wash tanks.

Another object of this invention is to provide a method and apparatus for efiiciently removing salt deposited on wash tank heaters.

A further object of this invention is to heat only a minimum amount of the water injected into crude oil wash tanks.

Another object of this invention is to provide a novel heater construction for wash tanks which is supported in such a manner that the various parts thereof may expand and contract without damaging the heater.

A still further object of this invention is to provide a simply constructed wash tank heater which may be economically manufactured.

and contraction of the fire box 34.

ice

Other objects and advantages of the invention will be evident from the following detailed description, when read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

Figure 1 is a vertical sectional view through a crude oil wash tank having my novel heater secured therein, with the heater also being shown in section.

FigureZ is a sectional view as taken along lines 22 of Fig. 1.

Figure 3 is another sectional view as taken along lines 33 of Fig. 1.

Referring to the drawings in detail, and particularly Fig. 1, reference character 4 designates a crude oil wash tank having a valved water drain line 6 in the lower end thereof and a valved crude oil outlet 8 in the upper end thereof. A circular opening or aperture 10 is formed in one side wall of the tank 4 at approximately the medial portion (in height) of the tank to receive my novel heater which is generally indicated at 12.

The heater 12 comprises an outer tubular-shaped sleeve or shield 14 having a pair of circumferentially extending flanges 16 on the outer periphery thereof. The flanges 16 are spaced in such a manner to receive the wall of the wash tank 4 therebetween and support the heater 12 in the opening 10. A plurality of circumferentially spaced bolts 18 extend through the flanges 16 and the wall of the tank 4, and suitable sealing means (not shown) are preferably interposed between the inner faces of the flanges 16 and the respective wall of the tank to prevent leakage around the flanges 16 and out through the opening 10. It is also preferred that the shield 14 be of .a diametrical size to closely fit in the opening 10.

The inner end 2t? of the shield 14 is open and freely suspended in the tank 4, whereby the shield 14 may expand and contract with changing temperature conditions without placing a stress on either the shield 14 or the tank 4. The lower half portion of the shield 14 is cut away at 22 from the inner end '200f the shield to a point 24 in proximity with the flanges 16 and the opening 10. An inlet conduit 26, having a valve 28 therein, communicates with the shield 14 at the lower outer end thereof to introduce the combined crude oil and water being produced from one or more oil wells (not shown) into the wash tank 4. Therefore, the incoming crude oil and water will flow along the lower portion of the shield 14 and out through the cut-away portion 22 into the tank 4, as will be more fully hereinafter set forth. The outer end 30 of the shield 14 is provided with an annular-shaped cover 32 which extends inwardly to the fire box, generally indicated at 34, of the heater 12. The cover 32 is rigidly secured to the outer end 30 of the shield 14 and the outer end of the fire box 34 in any suitable manner to prevent leakage of fluid through the outer end 30 of the shield.

The fire box 34 comprises an outer tubular-shaped member 36 which extends inwardly from the cover 32 to approximately the inner end 20 of the shield 14. The inner end of the member 36 is closed by a cover 38 and is freely suspended in the tank 4 to facilitate expansion An annular-shaped cover 40 is secured. to the outer end of the member 36 by a plurality of bolts 42, and extends inwardly to another tubular member 44 which forms a combustion chamber 46 in the fire box 3-1. For a practical construction, the cover ill is preferably in the form of a circumferential flange extending outwardly from the inner tubular member 44. The inner end 48 of the inner member 44 is disposed in outwardly spaced relation with respect to the cover 33 of the outer tubular member 36 and is closed by a cover 50. Also, a bracket or block 52 is securedgin the inner end portion of the outer member 36 to slidingly support the inner end portion of the inner member 44. Therefore, the inner member 44 may expand and contract without contacting the cover 38 of the outer member 36 and placing undue strain on any portion of the heater 12.

A cover 54 is bolted to the outer end of the inner tubular member 44 and has an aperture 56 in the central portion thereof providing an inlet for air to the combustion chamber 46, as will be more fully hereinafter set forth. Another aperture 58 is formed in the cover 54 above the air inlet 56 to receive and support a fuel conduit 60. The conduit 60 extends throughout the length of the combustion chamber 46 and has its inner end 62 abutting the cover 50. Also, a bracket 64 is secured on the inner face of the cover to support the inner end 62 of the fuel conduit 60. The opposite end of the conduit communicates with any suitable supply of fuel (not shown), such as a gas gathering system.

As most clearly shown in Fig. 3, a plurality of discharge apertures 66 are formed in spaced relation in the bottom of the fuel conduit 60, and a nozzle 68 is supported below each of the apertures 66. Each nozzle 68 has a lower flared end 70 to disperse the burning fuel in the combustion chamber 46, and each nozzle 68 is supported in I, downwardly spaced relation from the conduit 60 by a pair of straps 72.

Therefore, the air entering the combustion chamber 46 through the aperture 56 can combine with the fuel discharging through the apertures 66 to provide a combustible mixture in the nozzles 68.

A fresh water spray conduit 74 (Fig. 1) extends through the cover 32 of the shield 14 above the fire box 34. The conduit 74 is sealed by any suitable means (not shown) in the cover 32 and extends to a point substantially conterminous with the inner end 20 of the shield 14. The inner end 76 of the conduit 74 is closed-off and suspended from the shield 14 by a suitable bracket 78. A plurality of apertures 80 are formed in spaced relation in the bottom of the conduit 74 to spray streams of fresh water onto the top of the fire box 34 for removing salt depositing on the fire box, as will be more fully hereinafter set forth. A suitable valve 82 is interposed in the conduit 74 to control the discharge of fresh water through the apertures 80, and the conduit 74 communicates with a suitable supply (not shown) of fresh water.

Operation During the normal use of the tank 4, the water level 84 is ordinarily maintained in the upper portion of the tank above the heater 12, and crude oil accumulates above the water for discharge through the crude oil outlet 8. The water drain line 6 is opened as necessary to retain the water level 84 at the desired height Production fluid, consisting of crude oil and brine water from one or more producing oil wells, is directed through the inlet conduit 26 into the lower outer portion of the shield 14. This production fluid then flows along the bottom portion of the shield 14 and out through the cut-away portion 22 into the lower portion of the tank 4. As the production fluid discharges through the cut-away portion 22, the free water contained in the fluid. falls out by gravity into the lower portion of the tank 4, and does not become heated by the heater 12 to any appreciable extent. The remaining production fluid, being mostly oil and lighter than the water, ascends through the tank 4 around the fire box 34 and out the open end 20 of the shield 14 to the upper portion of the tank 4. As the crude oil circulates around the fire box 34, it is heated to facilitate removal of the remaining water from the crude.

In operation of the heater 12, fuel is supplied through the conduit 60 and discharged through the apertures 66 and the nozzles 68. Simultaneously, air is drawn in through the inlet aperture 56 to combine with the fuel and provide a combustible mixture. As this mixture burns, it is discharged through the nozzles 68 toward the lower portion of the combustion chamber 46. From the combustion chamber 46 the burning fuel and the products of combustion are discharged through a series of apertures 86 (formed in the inner tubular member 44) into the outer tubular member 36. As most clearly shown in Fig. 2, the majority of the apertures 86 are formed in the lower portion of the inner tubular member 44 to direct the major portion of the burning fuel and hot products of combustion into the lower portion of the outer tubular member 36, thereby distributing the heat in the fire box 34. However, the hot products of combustion will tend to rise in the outer tubular member 36 and will therefore circulate around the inner tubular member 44 until they are exhausted through an exhaust conduit 88 extending outwardly from the lower outer end of the outer tubular member 36. The discharge or exhaust conduit 88 communicates with a vertical flue or stack 90 which tends to draw the products of combustion from the fire box 34 in the usual manner.

It will be observed that the heater 12 is immersed in the brine water in the tank 4, therefore salt will precipitate from the brine water onto the hot fire box 34, and particularly onto the upper surface or crown portion of the fire box. This deposited salt forms an insulation around the fire box 34 and inhibits the transfer of heat to the contents of the tank 4. Periodically, the valve 82 is opened to provide a flow of fresh water through the conduit 74 and discharge apertures 81 This fresh water will be sprayed onto the top of the fire box 34 and will wash away the deposited salt. It will also be observed that this washing or cleansing action may be done during the normal operation of the heater 12 and the wash tank 4, thereby preventing the necessity of shutting down the Wash tank 4 and removing the heater 12 for removing salt from the fire box.

From the foregoing it will be apparent that the present invention provides eflicient utilization of the heat generated in crude oil wash tanks. The free water contained in the production fluid entering the tank will be removed prior to circulation of the production fluid around the heater to minimize the transfer of heat to the free water, and provide the maximum transfer of heat to the remaining production fluid. The present heater is constructed and supported in a wash tank in such a manner that all elements of the heater may expand and contract without placing undue stresses on any portion of the heater or the wash tank. It will also be apparent that the present invention provides a novel apparatus for removing salt depositing on the heater without the necessity of removing the heater from the wash tank.

Changes may be made in the combination and arrangement of parts heretofore set forth in the specification and shown in the drawings without departing from the scope and spirit of the invention as defined in the following claims.

I claim:

1. A heater for a crude oil wash tank or the like containing brine water and having an opening in one side wall thereof below the normal water level and a crude oil outlet above the normal water level, comprising a tubular shield member of a size to extend horizontally through said opening, flanges on the outer periphery of said shield for engaging the tank around the edge of said opening to support said shield and prevent leakage between said shield and the periphery of said opening, the inner end of said shield being open and suspended freely in the tank, a fire box' secured in the outer end of said shield and extending inwardly in said shield in the manner of a cantilever, the outer end ofsaid shield being closed around said fire box, a fuel supply line extending into said fire box for directing combustion in said fire box, an exhaust flue connected to the outer end of said fire box for discharging the cooled products of combustion, and a fluid inlet in the outer end portion of'said shield below said fire box, whereby the free water in the inlet fluid will fall out into the lower portion of the tank at the inner end of said shield and will absorb a minimum of the heat liberated from said fire box.

2. A heater as defined in claim 1 characterized further in that the lower half portion of said shield is removed from the inner end of said shield to a point immediately inward of said flanges to provide a separation of the free water from the inlet fluid immediately upon entry of the inlet fluid into the tank.

3. A heater as defined in claim 1 characterized further in having a supply of fresh water, and a perforated conduit extending from said supply into said shield above said fire box for spraying fresh water onto the top portion of said fire box and removing deposited salt.

4. A heater as defined in claim 3 characterized further in that said fire box is cylindrical in configuration and said fresh water is sprayed onto the crown of said fire box.

5. A heater for use immersed in a brine water environment, comprising a central perforated member forming a combustion chamber, fuel supply means in said chamber for supporting combustion, a closed fire box surrounding said member and having its outer surface exposed to the brine water, said fire box also having an exhaust in the lower portion thereof for discharging the products of combustion, said member having a length less than the fire box and being slidingly supported in the fire box, a controlled supply of fresh water, and a spray supported on and above said fire box and connected to the fresh water supply for spraying fresh water onto the upper surface of said fire box, whereby salt deposited on the upper surface of said fire box may be Washed off by the fresh water when desired.

6. A heater as defined in claim 5 characterized further in that said fire box is cylindrical in configuration and extends horizontally, and said spray is arranged to spray the fresh water onto the crown of said fire box.

7. A heater as defined in claim 6 characterized further in that said central member is tubular in configuration with perforations principally in the lower portion thereof to disperse the heat of combustion around the periphery of said fire box.

References Cited in the file of this patent UNITED STATES PATENTS 1,926,252 Wright et al. Sept. 12, 1933 2,421,375 Elliot June 3, 1947 2,579,184 Glasgow et a1 Dec. 18, 1951 2,634,164 Drake Apr. 7, 1953 2,740,492 Williams Apr. 3, 1956 

